/Engine/Source/Runtime/Slate/Public/Framework/Text/TextLayout.h
Set the iterator to use to detect appropriate soft-wrapping points for lines (or null to go back to using the default)
void SetLineBreakIterator ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IBreakIterator](API\Runtime\Core\Internationalization\IBreakIterator) > InLineBreakIterator )